docs(openspec): add OpenSpec changes for FN-005, FN-006, FN-008, FN-009, FN-010

- Add frontend-foundation change (FN-005) with 46 tasks
- Add deployment-config change (FN-006) with 27 tasks
- Add runfusion-poc/opencode-poc change (FN-008) with 25 tasks
- Add config-secrets change (FN-009) with 31 tasks
- Add codeserver-spawn change (FN-010) with 38 tasks
- Include project specsheet and configuration
- Archive completed deployment-config change

openspec/changes/archive/2026-05-14-frontend-foundation/specs/api-client/spec.md

@@ -0,0 +1,28 @@
+## ADDED Requirements
+
+### Requirement: API client handles all backend endpoints
+The system SHALL provide a typed HTTP client for all backend API endpoints.
+
+#### Scenario: GET request
+- **WHEN** the client calls api.get('/projects')
+- **THEN** it sends a GET request to /api/v1/projects
+- **AND** returns typed Project[] data
+- **AND** includes the Authorization header with the current access token
+
+#### Scenario: POST request
+- **WHEN** the client calls api.post('/projects', data)
+- **THEN** it sends a POST request with JSON body
+- **AND** returns typed Project data
+
+#### Scenario: Error handling
+- **WHEN** a request returns 4xx or 5xx
+- **THEN** the client throws an ApiError with status code and message
+- **AND** the error can be caught and displayed to the user
+
+### Requirement: API client supports request/response types
+The system SHALL use TypeScript interfaces matching the backend Pydantic schemas.
+
+#### Scenario: Type safety
+- **WHEN** a developer uses the API client
+- **THEN** request and response types are checked at compile time
+- **AND** mismatches produce TypeScript errors